Reed Value position(1968 Evinrude 18hp).

[iboat2011]

Hello,

I have a question regarding to reed value and the stop behind it. When re-assemble them, do I need to cover all those holes on the leaf plate when screw reed value back? Is there any specific position that I have to put the leaf stop behind the reed value? How tight do I need to screw the reed value and leaf stop to the plate so fuel/air can make into the intake manifold but not letting anything out it?

Thanks a lot in advance!
Andrew

 

[Kaplooi]

Re: Reed Value position(1968 Evinrude 18hp).

It's critical that the reed valves cover all the holes in leaf plate. If the valves are not completely sealing the holes there will be no positive pressure created in the crank case to force the fuel/oil mix into the cylinders during the piston's downstrokes. Also, I believe the pressure/vacuum cycling is responsible for running your fuel pump diaphragm so you can basically expect your engine not to run if your reed valves are not installed properly. As for specific torque specs and how to position the leaf stop you'll have to check a service manual. I had a 1973 20hp that's probably similar but I don't recall how much you can adjust the stop positioning. I think the most important thing is to make sure the stops are centered behind each leaf so they don't get sucked open too much during the piston compression strokes.

 

[194269]

Re: Reed Value position(1968 Evinrude 18hp).

As Kapooi said the reeds must be center and cover all holes, the reed stops must be centered over the reeds. There is a screw, lock washer and nut that holds the assembly to gether. Tighten the screw snuggly and put some lock tight on the nut. Assemble it with the screw head facing out.

 

[wilde1j]

Re: Reed Value position(1968 Evinrude 18hp).

Why did you ever take the reed valve assembly apart? They almost never cause a running problem (unless messed with).

 

[iboat2011]

Re: Reed Value position(1968 Evinrude 18hp).

It's critical that the reed valves cover all the holes in leaf plate. If the valves are not completely sealing the holes there will be no positive pressure created in the crank case to force the fuel/oil mix into the cylinders during the piston's downstrokes. Also, I believe the pressure/vacuum cycling is responsible for running your fuel pump diaphragm so you can basically expect your engine not to run if your reed valves are not installed properly. As for specific torque specs and how to position the leaf stop you'll have to check a service manual. I had a 1973 20hp that's probably similar but I don't recall how much you can adjust the stop positioning. I think the most important thing is to make sure the stops are centered behind each leaf so they don't get sucked open too much during the piston compression strokes.

Kaplooi, Thanks you so much for the quick reply!

One more question, since the leaf stop is not flat(like ")" shape), which side of the leaf stop should attach to the reed, (| or )|?